johngg@abouriou:~$ perl -Mstrict -Mwarnings -MData::Dumper -E '
my @list = qw{ 1 2 3 4 5 6 7 8 9 10 11 12 };
my( $nCols, $nRows ) = ( 4, 3 );
my @AoA = sub {
   my @tAoA;
   push @tAoA, [ splice @_, 0, $nCols ]
      while @_;
   return @tAoA;
   }->( @list );

print Data::Dumper->Dumpxs( [ \ @list, \ @AoA ], [ qw{ *list *AoA } ] );'
@list = (
          '1',
          '2',
          '3',
          '4',
          '5',
          '6',
          '7',
          '8',
          '9',
          '10',
          '11',
          '12'
        );
@AoA = (
         [
           '1',
           '2',
           '3',
           '4'
         ],
         [
           '5',
           '6',
           '7',
           '8'
         ],
         [
           '9',
           '10',
           '11',
           '12'
         ]
       );